[turbofan] compute arguments length in deoptimizer

src/compiler/common-operator.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_COMMON_OPERATOR_H_
 #define V8_COMPILER_COMMON_OPERATOR_H_
 
 #include "src/assembler.h"
 #include "src/base/compiler-specific.h"
 #include "src/compiler/frame-states.h"
@@ skipping 279 matching lines @@
 enum class OsrGuardType { kUninitialized, kSignedSmall, kAny };
 size_t hash_value(OsrGuardType type);
 std::ostream& operator<<(std::ostream&, OsrGuardType);
 OsrGuardType OsrGuardTypeOf(Operator const*);
 
 SparseInputMask SparseInputMaskOf(Operator const*);
 
 ZoneVector<MachineType> const* MachineTypesOf(Operator const*)
     WARN_UNUSED_RESULT;
 
-// The ArgumentsElementsState can either describe an unmapped arguments backing
-// store or the backing store of the rest parameters. IsRestOf(op) is true in
-// the second case.
+// The ArgumentsElementsState and ArgumentsLengthState can either describe an
+// unmapped arguments backing store or the backing store of the rest parameters.
+// IsRestOf(op) is true in the second case.
 bool IsRestOf(Operator const*);
 
 // Interface for building common operators that can be used at any level of IR,
 // including JavaScript, mid-level, and low-level.
 class V8_EXPORT_PRIVATE CommonOperatorBuilder final
     : public NON_EXPORTED_BASE(ZoneObject) {
  public:
   explicit CommonOperatorBuilder(Zone* zone);
 
   const Operator* Dead();
@@ skipping 48 matching lines @@
   const Operator* LoopExit();
   const Operator* LoopExitValue();
   const Operator* LoopExitEffect();
   const Operator* Checkpoint();
   const Operator* BeginRegion(RegionObservability);
   const Operator* FinishRegion();
   const Operator* StateValues(int arguments, SparseInputMask bitmask);
   const Operator* TypedStateValues(const ZoneVector<MachineType>* types,
                                    SparseInputMask bitmask);
   const Operator* ArgumentsElementsState(bool is_rest);
+  const Operator* ArgumentsLengthState(bool is_rest);
   const Operator* ObjectState(int pointer_slots);
   const Operator* TypedObjectState(const ZoneVector<MachineType>* types);
   const Operator* FrameState(BailoutId bailout_id,
                              OutputFrameStateCombine state_combine,
                              const FrameStateFunctionInfo* function_info);
   const Operator* Call(const CallDescriptor* descriptor);
   const Operator* TailCall(const CallDescriptor* descriptor);
   const Operator* Projection(size_t index);
   const Operator* Retain();
   const Operator* TypeGuard(Type* type);
@@ skipping 14 matching lines @@
   Zone* const zone_;
 
   DISALLOW_COPY_AND_ASSIGN(CommonOperatorBuilder);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_COMMON_OPERATOR_H_